(1) Field of the Invention
This invention relates to a process for the removal of asbestos filled linings or coatings, and more specifically to a process useful for removing old asbestos-filled linings or coatings applied on ceilings, side walls or outer walls or outer walls of various buildings and the like without impairing the health of workers and causing environmental pollution. The present invention is also concerned with a water jet device suitable for use in the practice of the above process.
(2) Description of the Related Art
The severe health hazard of asbestos has become a great public concern. Asbestos has also been used in a large volume as an additive for conventional spray coating compositions. It has been employed widely for finishing the interiors of schools, hospitals and many other buildings.
The carcinogenicity of asbestos has however been discovered in recent years. In addition, asbestos has started scattering and floating from old asbestos-filled linings or coatings due to their deterioration. It is hence required to remove such asbestos-filled linings or coatings and to apply asbestos-free linings or coatings in many buildings such as schools.
A great deal of asbestos dust is caused to scatter into the air upon removal of such linings or coatings. An extremely strict standard is therefore required for their removal so as to protect workers from the hazardous substance and also to prevent the environmental pollution of the surrounding atmosphere.
Dust-protective working wear having perfect air-tightness is used to protect workers upon conducting the removal of asbestos-filled linings or coatings. It is also required to completely shut off the work area, for example, the windows and access openings of a building under work from the external atmosphere in order to prevent the environmental pollution.
As a method for peeling off asbestos-filled linings or coatings, metal knives or like tools have heretofore been used. This method is however accompanied by the following drawbacks. Namely, it requires scaffolding where asbestos-filled linings or coatings are located on high places such as ceilings and walls. Since it is indispensable to peel off the asbestos-filled linings or coatings completely, the work is very tough and its efficiency is very low.
There is hence an outstanding demand for the development of a method or process which permits easy and complete removal of asbestos-filled linings or coatings without pollution of the workers and surrounding environment. There is also another demand for the development of an apparatus or device which may be used for the above-mentioned purpose.